Synthesis of 1,4-Dimethyl-9,10-Anthraquinone from 1,4-Naphthoquinone and 2,4-Hexadiene in the Presence of Heteropoly Acids

Abstract

The synthesis of 1,4-dimethyl-9,10-anthraquinone (DMAQ) from 1,4-naphthoquinone and 2,4‑hexadiene was studied based on a new one-step method developed by the authors for the synthesis of substituted anthraquinones. A solution of high-vanadium heteropoly acid with the empirical formula H₁₇P₃Mo₁₆V₁₀O₈₉ (HPA-10) was used as a bifunctional (acid and oxidation) catalyst. It was found that a reaction with 2,4-hexadiene, unlike other methylbutadienes, does not proceed so smoothly, and it leads to the formation of a mixture of DMAQ, its dihydro derivative, and tarry products. Possible reasons for the results obtained are discussed.